应用蒙特卡罗方法进行大物件放射测量仪的探测效率校正

he accuracy must be guaranteed when radioactive materials are measured. Otherwise, it will lead to undetected errors which may result in radiation releases. In order to measure a large volume of radioactive materials in nuclear power plant accurately，we need to determine the deviation in measurement which depends on different locations of radioactive materials in the measuring instrument. At first, a calculating model is developed and compared with the experimental data. It turned out that the calculating model is correct. Then, by calculating spatial response function, the counting efficiency of different locations relative to that of the center in the measuring instrument can be obtained, according which the uniform areas of spatial response function can be determined. Meanwhile, considering the characteristics of radioactive materials to be measured, the efficiency of radioactive materials of different materials and different densities would be calculated under different energy by Monte Carlo method. And the results obtained by this approach could be used for the practical correction of the measuring instrument.